2026 ICD-10-CM Diagnosis Code N15.9Renal tubulo-interstitial disease, unspecified
ICD-10-CM Codes›N00–N99›N10-N16›N15
- Billable — Valid for Submission
- Chronic Condition
N15.9 is a billable ICD-10-CM diagnosis code for renal tubulo-interstitial disease, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 698 through 700. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nephritis; nephrosis; renal sclerosis.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- BK virus nephropathy
- Disease caused by BK polyomavirus
- Hereditary tubulointerstitial disorder
- Infectious disorder of kidney
- Perinephritis
- Post-renal transplant nephropathy caused by BK polyomavirus
- Renal impairment caused by Polyomavirus
- Tubular renal disease with cardiomyopathy syndrome
- Urinary tract infection following procedure
- Viral kidney infection
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Infection of kidney NOS
Type 1 Excludes
- urinary tract infection NOS N39.0
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Disease, diseased - See Also: Syndrome;
- tubulo-interstitial - N15.9
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Disease, diseased
- tubulo-interstitial
- Infection, infected, infective(opportunistic)
- kidney (cortex) (hematogenous)
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Perinephritis
inflammation of the connective and adipose tissues surrounding the kidney.Kidney
body organ that filters blood for the secretion of urine and that regulates ion concentrations.
Patient EducationClinical
Kidney Diseases
You have two kidneys, each about the size of your fist. They are near the middle of your back, just below the rib cage. Inside each kidney there are about a million tiny structures called nephrons. They filter your blood. They remove wastes and extra water, which become urine. The urine flows through tubes called ureters.
Read the full article at MedlinePlus
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Convert N15.9 to ICD-9-CMHistory
Code HistoryHistory
Questions About N15.9Overview
Is N15.9 (Other renal tubulo-interstitial diseases) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report renal tubulo-interstitial disease, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does N15.9 group to?
When renal tubulo-interstitial disease, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 698, 699, 700, with relative weights from 0.6899 to 1.6544 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of N15.9?
Under the General Equivalence Mappings, renal tubulo-interstitial disease, unspecified converts to ICD-9-CM 583.9 (nephritis NOS) and 590.9 (infection of kidney NOS). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:
- The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
- The condition places limitations on self-care, independent living, and social interactions.
